/**
 *    Copyright (C) 2025-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the Server Side Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#include "mongo/db/ftdc/collection_metrics.h"

#include "mongo/bson/bsonelement.h"
#include "mongo/db/commands/server_status/server_status.h"
#include "mongo/db/service_context.h"

namespace mongo {
namespace {
const auto ftdcCollectionMetrics = ServiceContext::declareDecoration<FTDCCollectionMetrics>();

class FTDCCollectionMetricsSection : public ServerStatusSection {
public:
    using ServerStatusSection::ServerStatusSection;

    bool includeByDefault() const override {
        return true;
    }

    BSONObj generateSection(OperationContext* opCtx, const BSONElement&) const override {
        return FTDCCollectionMetrics::get(opCtx).report();
    }
};

const auto& collectionMetricsSection =
    *ServerStatusSectionBuilder<FTDCCollectionMetricsSection>("ftdcCollectionMetrics")
         .forShard()
         .forRouter();
}  // namespace

FTDCCollectionMetrics& FTDCCollectionMetrics::get(ServiceContext* svcCtx) {
    return ftdcCollectionMetrics(svcCtx);
}

FTDCCollectionMetrics& FTDCCollectionMetrics::get(OperationContext* opCtx) {
    return get(opCtx->getServiceContext());
}

void FTDCCollectionMetrics::onCompletingCollection(Microseconds duration) {
    const auto micros = durationCount<Microseconds>(duration);
    _collectionsCount.fetchAndAdd(1);
    _collectionsDurationMicros.fetchAndAdd(micros);
    if (micros >= _collectionPeriodMicros.load()) {
        _collectionsStalled.fetchAndAdd(1);
    }
}

BSONObj FTDCCollectionMetrics::report() const {
    BSONObjBuilder bob;
    bob.append(kCollectionsCountTag, static_cast<long long>(_collectionsCount.loadRelaxed()));
    bob.append(kCollectionsDurationTag,
               static_cast<long long>(_collectionsDurationMicros.loadRelaxed()));
    bob.append(kCollectionsStalledTag, static_cast<long long>(_collectionsStalled.loadRelaxed()));
    return bob.obj();
}

}  // namespace mongo
